KR20110005850A - Method of machining vulnerable material substrate - Google Patents

Abstract

Provided is a processing method of a brittle material substrate capable of stable laser brake treatment. (A) forming a first initial crack so as to be spaced apart from the first substrate end when processing along the scribe scheduled line from the first substrate end to the second substrate end; and (b) The beam spot of the first laser irradiation is relatively moved from the first substrate end side to the second substrate end to be heated, and a coolant is injected by cooling to a portion immediately after the passage, and the depth direction generated in the scribe scheduled line is generated. Forming a scribe line having a finite depth using a stress gradient; (c) forming a second initial crack between the first substrate end or the first substrate end and the first initial crack; d) A step of relatively penetrating or completely dividing the scribe line by moving the beam spot of the second laser irradiation relatively from the first substrate end to the second substrate end.

Description

Processing method of brittle material substrate {METHOD OF MACHINING VULNERABLE MATERIAL SUBSTRATE}

According to the present invention, by applying a laser beam to a brittle material substrate to perform local heating, and then cooling along the heating portion, cracks having a finite depth are exploited by using thermal stress generated between the substrate surface and the inside of the substrate. It relates to a processing method of a brittle material substrate to be formed. In addition, the present invention irradiates the first laser beam along the scribe scheduled line set on the substrate to form a scribe line composed of cracks of finite depth on the substrate, and then the second laser. A method of processing a brittle material substrate that irradiates a beam to deeply penetrate this scribe line or to fully divide it.

Here, a brittle material substrate means a glass substrate, ceramics of a sintered material, single crystal silicon, a semiconductor wafer, a sapphire substrate, a ceramic substrate, etc.

When a laser beam is irradiated to a brittle material substrate such as a glass substrate, the beam spot formed on the substrate is scanned, heated in a line shape, and a laser scribe process in which a coolant is injected by cooling immediately after heating is used. Compared with the mechanical processing by this, the generation of cullets can be reduced, and the cross-sectional strength can be improved.

Therefore, laser scribing is employ | adopted in various manufacturing processes which require the division | segmentation of a glass substrate etc. including a flat panel display.

Generally, in laser scribing, an imaginary line (called a scribe scheduled line) to be divided from now on is set. From the position of the initial crack in which an initial crack was formed at the substrate end, which is the beginning of the scribe scheduled line, with a cutter wheel or the like, and a beam spot and a cooling spot (region where the refrigerant is injected) were formed at the beginning. Scan along the scheduled scribe line. At this time, as a result of the stress gradient generated on the basis of the temperature distribution generated near the scribe scheduled line, line-shaped cracks are formed (see Patent Document 1, Patent Document 2, and Patent Document 3).

By the way, in the linear crack formed by scanning a laser beam with respect to a brittle material board | substrate, the "finite depth crack" which the front-end | tip of a crack depth direction does not reach to the back surface of a board | substrate, and a crack is a back surface of a board | substrate There exists a "through crack" (for example, refer patent document 2) which reaches to and divides a board | substrate at once.

The cutting line formed by the former "crack of finite depth" is called a scribe line, and the dividing line by the latter through crack is called a full cut line. These are formed by different mechanisms.

7 is a cross-sectional view of a substrate that schematically illustrates the mechanism by which cracks of finite depth are formed. That is, the compressive stress HR generate | occur | produces in the board | substrate GA as shown in FIG.7 (a) by preceding laser heating. Subsequently, as a result of cooling after heating, as shown in Fig. 7B, tensile stress CR is generated on the substrate surface. At this time, the compressive stress HR moves inside the substrate by the movement of heat, and an internal stress field Hin is formed. As a result, as shown in FIG.7 (c), the stress gradient of a depth direction generate | occur | produces and the crack Cr is formed.

Under the conditions in which the cracks Cr are formed by the above mechanism, since the compressive stress field Hin existing inside the substrate blocks the penetration of further layers in the depth direction of the cracks Cr, the cracks Cr are inside the substrate. It stops in front of the compressive stress field Hin of, and in principle, the crack Cr becomes finite depth. Therefore, in order to completely divide a board | substrate, after a scribe line of finite depth by the crack Cr is formed, you must perform a brake process further. On the other hand, the processing cross section of the scribe line by crack Cr is very beautiful (the surface unevenness | corrugation is small), and also it is excellent in linearity, and is an ideal state as a processing cross section.

FIG. 8: is a perspective view (FIG. 8 (a)) and a top view (FIG. 8 (b)) of the board | substrate which showed typically the mechanism by which a through crack is formed. FIG. In other words, the compressive stress HR is generated on the surface of the substrate by the beam spot BS of the laser beam scanned from the position of the initial crack TR. At the same time, tensile stress CR is generated on the substrate surface by the cooling spot CS behind the beam spot BS. As a result, a stress gradient in the front-rear direction is formed on the scan line (on the scribe plan line L), and through this stress gradient, a force for tearing the substrate from side to side in the scan line direction acts to form a through crack. The substrate is divided.

When this "penetration crack" is formed, it is convenient in that a board | substrate can be segmented (full cut) without performing a brake process, and division by this mechanism may be desired depending on a processing use, Compared with the processing cross section of the scribe line mentioned above, the linearity of the processing cross section of a full cut line may be impaired, and also the quality (unevenness | corrugation of surface) of the cross section of a full cut line is compared with the scribe line mentioned above. Falls.

In addition, whether a scribe line is formed or a full cut line is formed by laser scribing, heating conditions (laser wavelength, irradiation time, output power, scanning speed, etc.), cooling conditions (refrigerant temperature, injection amount, injection position, etc.), It depends on the thickness of the substrate and the like. Generally, when the plate | board thickness of a glass substrate is thin, it becomes easy to become a full cut line compared with the case where it is thick, and the process window of the processing conditions which can form a scribe line is narrow. Moreover, there exists a tendency for a full cut line to form easily, so that it becomes radical conditions in which a board | substrate is rapidly heated and quenched.

In view of the above, when it is desired to perform the segmentation processing having excellent cross-sectional quality on a glass substrate or the like, laser scribing is performed by selecting heating conditions and cooling conditions of a mechanism in which a scribe line is formed, not a full cut line. The brake process is performed.

As a brake processing method performed after laser scribing, a mechanical brake processing in which a brake bar or the like is applied to a scribe line to apply a bending moment may be used. In the case of a mechanical brake process, a cullet may generate | occur | produce when a large bending moment is applied to a board | substrate. Therefore, in the manufacturing process which avoids generation | occurrence | production of a cullet, it is necessary to form a scribe line as deep as possible, and to make it possible to apply a brake process only by applying a small bending moment.

Thus, a second laser irradiation is performed along the scribe line formed by laser scribing to further penetrate the crack of a finite depth (in this case, again, a braking process), or the crack penetrates to the back surface and divides it. Laser brake processing is performed (for example, see Patent Documents 1 to 3).

Japanese Laid-Open Patent Publication No. 2001-130921 Japanese Laid-Open Patent Publication No. 2006-256944 WO2003 / 008352 publication

Thus, by performing the laser scribing process which forms a scribe line by the 1st laser irradiation, and performing a laser brake process by the 2nd laser irradiation, the division process which suppressed generation | occurrence | production of a cullet becomes possible. However, when the scribe line formed by laser scribing, that is, the first laser irradiation, is shallow, it is difficult to reach the cracks to the back surface of the substrate by a later laser brake process. Therefore, in order to cut | disconnect a board | substrate completely by a laser brake process, it is necessary to form a deep scribe line at the time of a laser scribing process.

In addition, even when the substrate is not completely divided by the laser brake process, it is preferable to form a scribe line at least a little deeper in the laser scribing process, since it becomes easier to make a deeper scribe line by a later laser brake process. Do.

By the way, when it is going to form a scribe line deeper than before by laser scribing, it is necessary to change the heating conditions and cooling conditions at the time when the scribe line was formed so far. Specifically, the stress in the depth direction generated in the substrate is increased by increasing the laser output to increase the amount of heat input by heating or to increase the amount of refrigerant injection during cooling, and to be a radical condition where a temperature difference in the depth direction tends to occur more than ever. The gradient needs to be increased.

However, when attempting to shift to a heating condition and a cooling condition that increase the stress gradient while maintaining the processing order of conventional laser scribing, the first laser irradiation does not form a deep scribe line, and instead the crack penetrates the substrate. Discarded (the transition to the mechanism through which penetrating cracks are formed), a full cut line is formed. That is, by appropriately selecting the heating conditions and cooling conditions at the time of laser scribing, a shallow scribe line can be formed relatively easily, but trying to form a deep scribe line, a little from the conditions which have previously used heating conditions and cooling conditions. Even if you try to change to extreme conditions, the range of settable heating conditions and cooling conditions does not exist, or even if they exist, the settable range (process window) is narrow and unstable, and the transition to the condition that a full cut line is formed suddenly occurs. It was difficult to form a deep scribe line as expected.

In addition to the problem of shifting to a full cut line, there is also a problem that the phenomenon of "falling ahead" easily occurs. As shown in FIG. 9, the term "preferred" means that the beam spot BS is formed when the initial crack TR formed at the start end is heated in the vicinity of the start end of the scribe scheduled line L. FIG. This is a phenomenon in which the crack K is formed in a direction that cannot be controlled toward the front of the beam spot starting from the heating region by. When "winding forward" occurs, the scribe line along the scribe scheduled line L cannot be formed, and the straightness of the scribe line is remarkably impaired.

In order to form a deep scribe line, when the heating conditions or cooling conditions are shifted to more intense heating conditions or cooling conditions, the frequency of occurrence of such "winding over" increases.

Therefore, an object of the present invention is firstly to provide a processing method capable of forming a scribe line formed of a crack having a finite depth deeper than ever.

Moreover, a 2nd object is to provide the processing method which can form the scribe line stably by widening the process window of the heating conditions and cooling conditions which can form a scribe line instead of a full cut line.

Moreover, it aims at providing the processing method of the scribe line which is hard to generate | occur | produce "the rolling ahead" in 3rd.

In addition, the present invention provides a brittle material substrate which can stably perform a process of forming a scribe line on a substrate by laser scribing and then performing a laser break treatment to completely divide the substrate or to form a deeper scribe line. An object of the present invention is to provide a processing method. Moreover, an object of this invention is to provide the processing method of a brittle material board | substrate which can stably perform the division process which was excellent in the cross-sectional quality of a process cross section.

In the method of processing the brittle material substrate of the present invention, which is made to solve the above problems, the brittle material which sets the scribe scheduled line having the substrate end as the starting end with respect to the brittle material substrate, and forms a crack of finite depth along the scribe scheduled line As a method of processing a material substrate, a cutter wheel is pressed to form an initial crack spaced from the start end near the start end of the scribe scheduled line and at a position on the scribe scheduled line spaced from the start end toward the substrate. The beam spot formed on the substrate surface by laser irradiation is locally heated to a softening temperature or less by relatively moving along the scribe scheduled line while passing through the initial crack phase from the start end, and then immediately after the locally heated area. By cooling, a finite depth from the initial crack position Cracks thereof are formed along the scribe line.

According to the present invention, when forming an initial crack on a scribing scheduled line, the initial crack formation position is formed not at the substrate end of the brittle material substrate but at a position slightly spaced inward from the substrate end, and thus the initial crack. Is separated from the substrate end. The initial crack is formed by pressing the cutter wheel toward the direction of the scribe scheduled line, and the direction of the initial crack is directed to the line direction of the scribe scheduled line. The substrate is then locally heated by moving the beam spot relative along the scribe line, passing through the initial crack phase from the beginning of the scribe line. Furthermore, immediately after the locally heated region is cooled. At this time, since an initial crack does not exist in a board | substrate end, a crack does not advance from a board | substrate end. Then, the beam spot is advanced from the substrate end, and the top of the initial crack at a position slightly heated is heated (the initial crack surface is subjected to compressive stress and the crack does not proceed). At the point of cooling (the initial crack surface is subjected to tensile stress and the internal crack is subjected to compressive stress), fins of finite depth starting from the initial crack are formed.

At this time, even if the stress distribution in the front-rear direction (the scribe planned line direction) is formed in the vicinity of the substrate end and the force which tries to tear from side to side (the force for inducing a full cut line) acts, no initial crack is formed at the substrate end. Therefore, the full cut line which advances from a board | substrate end is not formed. Then, once a crack having a finite depth starting from the initial crack is formed, thereafter, a crack of finite depth is continuously formed on the scribe scheduled line with the scanning of the beam spot, and the desired scribe line is formed. Is formed. Since the situation in which a full cut line is hard to be formed is made in this way, even if the heating conditions and cooling conditions by a beam spot are changed into a more severe condition, it will not move to a full cut line, but instead a deep scribe line Will be formed.

According to the present invention, a full cut line is less likely to be formed during laser scribing, so that a process window (range of settable heating conditions and cooling conditions) capable of forming a scribe line composed of cracks of finite depth can be widened. As a result, the scribe line can be formed stably.

Furthermore, according to the present invention, even if the processing conditions (heating conditions and cooling conditions) of the laser scribe are changed to more extreme conditions than before, a scribe line instead of a full cut line can be formed, and as a result, the deep scribe above Lines can be formed. In addition, since no crack is formed at the substrate end, the occurrence of "winding over" can be suppressed.

In the above invention, as the cutter wheel, a grooved cutter wheel in which a main groove is formed at the blade tip may be used.

In the above invention, the separation distance from the beginning of the scribe scheduled line to the initial crack may be 2 mm to 7 mm.

Moreover, the other brittle material substrate processing method made | formed in order to solve the said subject carries out two laser irradiation in the following order along the scribe plan line from the 1st board | substrate end set to the brittle material board | substrate to the 2nd board | substrate end. The substrate is processed by performing the process.

(a) First, a first initial crack forming step of forming a first initial crack inside the substrate is performed on the scribe scheduled line near the first substrate end so as to be spaced apart from the first substrate end. (b) Subsequently, the beam spot of the first laser irradiation is relatively moved from the first substrate end side along the scribe scheduled line to the second substrate end to heat the substrate below the softening temperature, and immediately after passing the beam spot. A laser scribe process is performed in which a coolant is sprayed on a portion of the sintered coolant to form a scribe line having a finite depth along the scribe line, using a stress gradient in the depth direction generated in the scribe line.

At this time, by appropriately selecting the heating condition by the beam spot and the cooling condition by the cooling spot, a scribe line composed of a finite depth crack formed based on the stress gradient in the depth direction is formed so that a full cut line is not formed. Do not. Specifically, when the heating condition (e.g. increase in laser output) or the cooling condition (e.g. increase in refrigerant injection amount) becomes too severe, the temperature tends to become a full cut line rather than a scribe line. Do not make heating or cooling conditions too extreme. However, since no initial crack is formed in the first substrate end, it is difficult to generate a full cut line starting from the substrate end, and the process window that can be selected is widened, so that heating conditions having a larger temperature difference than in the prior art, Laser scribe processing can be performed under cooling conditions.

(c) Next, a second initial crack forming step of forming a second initial crack on at least one of the first substrate end or a scribe scheduled line between the first substrate end and the first initial crack is performed.

Thereby, the cutting line which guides the advancing direction of a crack at the next laser brake process is formed in the vicinity of a 1st board | substrate end.

(d) Subsequently, a laser brake process is performed in which the beam spot of the second laser irradiation is relatively moved along the scribe line from the first substrate end to the second substrate end to further infiltrate the scribe line further, or to divide it completely. Run

As a result, cracks progress from the first substrate end to the second substrate end, thereby making it possible to form a crack reliably, and furthermore, the direction in which the cracks are formed near the first substrate end by the second initial crack can be induced. As a result, uncontrollable cracks such as "winding over" can be prevented from being formed.

According to this invention, the scribe line formed by the laser scribing process can be made into a deep scribe line, or it can become a parting process simply.

In addition, since the process window (range that can be set as a processing condition) that can be set can be widened at the time of laser scribing, a deeper scribe line can be formed using more intense heating and cooling conditions than ever before. . In addition, by forming a deep scribe line, the settable process window (the range that can be set as a processing condition) is widened during the laser brake processing, and the scribe line can be stably formed deeper without shifting to a full cut, It can be completely segmented or stable.

In the second initial crack formation step of (c) of the invention, the second initial crack may be formed continuously along the scribe scheduled line from the first substrate end to the first initial crack.

As a result, during the next laser break process, the crack progresses along the scribe scheduled line from the first substrate end to the first initial crack, thereby completely eliminating the winding phenomenon.

In the above invention, the first initial crack and the second initial crack may be formed by pressing the cutter wheel. Thereby, the initial stage crack of a thin cutting line can be reliably formed even on the board surface separated from the board | substrate end.

In particular, by using a cutter wheel having a periodic groove formed at the tip of the blade, the tip of the blade is less likely to slip with respect to the substrate surface. Only by rolling, stable initial cracking can be formed. As a grooved cutter wheel having a cycle groove formed at the blade tip, specifically, a high penetrating blade tip "penett" (registered trademark) or "APIO" (registered trademark) manufactured by Mitsubishi Diamond Co., Ltd. can be used. Can be.

In the above invention, the first initial crack may be formed by pressing the cutter wheel, and the second initial crack may be formed by partial irradiation of the laser from the first initial crack phase toward the first substrate end side.

According to this, the 1st initial stage crack on a board | substrate can reliably form the initial stage crack of a thin cutting line by a cutter wheel. In addition, since the first initial crack is already formed in the second initial crack, the second initial crack is caused by advancing the crack by partial irradiation of the laser from the first initial crack image toward the first substrate end side. Can be derived.

In the above invention, the second initial crack may be formed deeper than the first initial crack. Specifically, for example, the pressing force of the cutter wheel when forming the second initial crack may be stronger than the first initial crack.

This makes it possible to simply deepen the depth of the crack in the subsequent laser brake process.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the substrate processing apparatus used when implementing the substrate processing method of this invention.
2 is a view showing the configuration of a cutter wheel with a periodic groove.
It is a figure which shows a part of the operation procedure of the machining method which is one Embodiment of this invention.
It is a figure which shows a part of the operation procedure of the machining method which is one Embodiment of this invention.
5 is a cross-sectional view schematically showing a stress gradient to be formed during laser brake processing.
It is a figure which shows a part of the operation procedure of the machining method which is another embodiment of this invention.
7 is a cross-sectional view schematically showing a mechanism in which cracks of a finite depth are formed.
8 is a perspective view and a plan view schematically showing a mechanism in which a full cut line is formed.
FIG. 9 is a diagram illustrating a winding phenomenon occurring at the substrate end. FIG.

Best Mode for Carrying Out the Invention [

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

First, an example of the substrate processing apparatus used when implementing the processing method of this invention is demonstrated.

1 is a schematic configuration diagram of a substrate processing apparatus LS1 capable of implementing the processing method of the present invention. Although the case where a glass substrate is processed is demonstrated as an example here, even if it is a brittle material substrate, such as a silicon substrate.

First, the whole structure of the substrate processing apparatus LS1 is demonstrated. A slide table which reciprocates in the front and rear direction of the paper (hereinafter referred to as the Y-direction) of FIG. 1 along a pair of guide rails 3 and 4 arranged in parallel on a horizontal stand 1 ( 2) is formed. The screw screw 5 is arrange | positioned along the front-back direction between both guide rails 3 and 4, The stay 6 fixed to the slide table 2 is screwed to this screw screw 5, By rotating the screw screw 5 forward and backward with a motor (not shown), the slide table 2 is formed to reciprocate along the guide rails 3 and 4 in the Y direction.

On the slide table 2, a horizontal pedestal 7 is arranged to reciprocate along the guide rail 8 in the left-right direction (hereinafter referred to as the X-direction) in FIG. The screw screw 10 rotated by the motor 9 is coupled to the stay 10a fixed to the pedestal 7, and the pedestal 7 is rotated by rotating the screw screw 10a forward and backward. Along the guide rail 8, it reciprocates in the X direction.

On the pedestal 7, the rotary table 12 which is rotated by the rotary mechanism 11 is formed, and the glass substrate A is attached on the rotary table 12 in a horizontal state. This glass substrate A is, for example, a mother substrate for cutting out a small unit substrate. The rotary mechanism 11 is configured to rotate the rotary table 12 around a vertical axis, and is formed so as to be able to rotate at an arbitrary rotational angle with respect to the reference position. In addition, the glass substrate A is fixed to the turntable 12 by the suction chuck.

Above the rotary table 12, the laser device 13 and the optical holder 14 are held by the attachment frame 15. As shown in FIG.

The laser device 13 may use a general thing for processing a brittle material substrate, and specifically, an excimer laser, a YAG laser, a carbon dioxide laser, a carbon monoxide laser, etc. are used. It is preferable to use the carbon dioxide laser which oscillates the light of the wavelength with the large energy absorption efficiency of a glass material for the process of the glass substrate A. FIG.

As for the laser beam radiate | emitted from the laser apparatus 13, the beam spot of a predetermined shape is irradiated on the glass substrate A by the optical holder 14 in which the lens optical system for adjusting a beam shape was integrated. The shape of the beam spot is excellent in that the shape having a long axis (elliptical shape, oblong shape, etc.) can be efficiently heated along the scribe scheduled line, but if the shape can be heated at a lower temperature than the softening temperature, The shape of the spot is not particularly limited. In this embodiment, an elliptic beam spot is formed.

In the attachment frame 15, a cooling nozzle 16 is formed in proximity to the optical holder 14. Coolant is injected from the cooling nozzle 16. Cooling water, compressed air, He gas, carbon dioxide gas, and the like can be used for the refrigerant, but compressed air is injected in the present embodiment. The cooling medium injected from the cooling nozzle 16 is directed to a position slightly away from the left end of the beam spot, so as to form a cooling spot on the surface of the glass substrate A. FIG.

Moreover, the cutter wheel 18 with a periodic groove is attached to the attachment frame 15 via the lifting mechanism 17. As shown in FIG. The cutter wheel 18 is used to temporarily descend from above the glass substrate A when forming the initial crack Tr in the glass substrate A. As shown in FIG.

Fig. 2 is a schematic view of a cutter wheel with a periodic groove, Fig. 2 (a) is a front view, and Fig. 2 (b) is a side view. The groove 18b of the periodic grooved cutter wheel 18 is periodically cut along the blade tip 18a (also for convenience of explanation in FIG. 2, the size of the groove 18b with respect to the blade tip 18 is increased. , Exaggerated than actual). Specifically, the groove pitch is formed in the range of 20 µm to 200 µm depending on the wheel diameter of 1 to 20 mm. Moreover, the groove depth is 2 micrometers-2500 micrometers.

By using such a cutter blade of a special blade tip, it is possible not only to form a crack penetrating deeper than a normal cutter wheel without a groove, but also to make the blade tip less slippery with respect to the substrate surface. The initial crack can be reliably formed in the substrate surface only by rolling the distance (about 1 mm to 2 mm).

Moreover, the camera 20 which can detect the alignment mark for positioning previously imprinted on the glass substrate A is mounted in the board | substrate processing apparatus LS1, and the camera 20 From the position of the detected alignment mark, the positional relationship between the position of the scribe plan line set on the board | substrate A and the rotation table 12 is calculated | required, and the falling position of the cutter wheel 18 and the irradiation position of a laser beam are It can be positioned accurately so as to be on a scribe schedule line.

Next, the processing operation procedure by the said substrate processing apparatus LS1 is demonstrated. FIG. 3 is a diagram showing a processing operation procedure of laser scribing until a scribe line having a finite depth is formed by the first laser irradiation, and FIG. 4 until the laser brake process is performed by the second laser irradiation. It is a figure which shows the processing operation procedure of a. 3 and 4 show only the main parts of FIG. 1.

First, as shown to Fig.3 (a), the glass substrate A is mounted on the rotating table 12, and is fixed by the suction chuck. The alignment mark (not shown) imprinted on the glass substrate A is detected by the camera 20 (FIG. 1), and based on the detection result, the scribing scheduled line, the rotation table 12, and the slide table (2), the position with the pedestal 7 is related. Then, by operating the rotary table 12 and the slide table 2, the position is adjusted so that the blade tip direction of the cutter wheel 18 stands side by side in the direction of the scribe scheduled line.

Subsequently, as shown in FIG. 3 (b), the base 7 (FIG. 1) is operated to move the turntable 12 to form a first initial crack in the glass substrate A. FIG. The cutter wheel 18 is brought near the substrate end A1 and above the position spaced apart from the first substrate end A1.

Next, as shown in FIG.3 (c), the lift mechanism 17 is operated and the cutter wheel 18 is lowered. Then, the end of the blade is pressed against the substrate A to form the first initial crack Tr1. At this time, the base 7 is moved about 2 mm to drive the cutter wheel 18 on the substrate, thereby forming a stable first initial crack Tr1.

Subsequently, as shown in FIG. 3 (d), the lifting mechanism 17 and the turntable 12 are returned to their original positions (the positions in FIG. 3 (a)) to operate the laser device 13 to operate the laser beam. Investigate. In addition, the refrigerant is injected from the cooling nozzle 16. At this time, heating conditions and cooling conditions, such as the laser power to be irradiated and the refrigerant injection amount, are set within a range where no penetration crack occurs (that is, no full cut) at the position of the first initial crack Tr1.

Since the first initial crack Tr1 is spaced apart from the substrate end (first substrate end A1) and formed at the substrate inner position, a force (in a full cut state) that attempts to tear left and right on the first substrate end A1. Even though the first substrate end A1 is in a difficult state of cracking, even when an initial crack is formed, the first substrate end A1 is less likely to have a full cut than the case where an initial crack is formed in the substrate end A1 in advance. Moreover, the process window which can select the conditions which are not full cut about heating conditions, such as the laser output to be irradiated, the refrigerant injection quantity, and cooling conditions, is widening. Therefore, as setting heating conditions and cooling conditions, you may select radical conditions, ie, conditions which can form a scribe line deeper, than when the initial stage crack is formed in the board | substrate edge.

Subsequently, as shown in FIG. 3E, the pedestal 7 is moved, and the beam spot of the laser beam formed on the substrate A, and the cooling spot by the refrigerant from the cooling nozzle 16, Allow scanning along the lines to be scribed.

By the above operation | movement, the scribe line which consists of the crack Cr of a finite depth starting from the position of the 1st initial stage crack Tr1 is formed in the board | substrate A. As shown in FIG. At this time, by selecting the heating conditions of the laser and the cooling conditions by the coolant appropriately (ie, the violent conditions in the range where the full cut is not performed) within the range where the through crack is not achieved, a deep scribe line that has been difficult until now can be formed. Moreover, the area | region in which the crack Cr is not formed exists in the board | substrate end (1st board | substrate end A1) of the board | substrate A on the 1st initial stage crack Tr1 side.

Next, the laser brake process will be described.

As shown to Fig.4 (a), the rotary table 12 is returned to the original position (position of Fig.3 (a)), and the lifting mechanism 17 is operated and the cutter wheel 18 is lowered.

Subsequently, as shown in FIG.4 (b), it moves so that the board | substrate A and the cutter wheel 18 may approach, the cutter wheel 18 may be applied to the 1st board | substrate end A1, and a 2nd initial stage may be provided to a board | substrate end. A crack Tr2 is formed. At this time, the table 12 may be moved continuously so that the second initial crack Tr2 may continue to the first initial crack Tr1.

The second initial crack Tr2 may be formed deeper than the first initial crack Tr1 by changing the pressure welding force. In this case, as described later, penetrating the crack deeply can be made simpler.

Subsequently, as shown in FIG.4 (c), the lifting mechanism 17 and the turntable 12 (base 7) are returned to the original position (position of FIG.3 (a)), and the laser apparatus 13 To operate the laser beam. Heating conditions, such as a laser output irradiated at this time, are mentioned later.

Subsequently, as shown in FIG.4 (d), the board | substrate A is moved and the beam spot formed on the board | substrate A is moved from the 1st board | substrate end A1 to the 2nd board | substrate end A2 along a scribe line. Inject). As a result, since the second initial crack Tr2 (that is, the first substrate end A1) starts and the deep crack Cr2 proceeds along the crack Cr (scribe line), the scribe line deeper than ever is The second substrate end A2 is formed.

Here, the heating condition at the time of laser brake process is demonstrated. About heating conditions, such as a laser output, although it may be the same as the time of 1st laser irradiation, it is preferable to set as follows.

In the laser brake process, the scanning speed is set faster than the first laser irradiation, the heating time at each point on the scribe line is shortened (laser output is set high), and the surface layer of the scribe line is set to heat only for a short time. This is for forming a stress gradient for deeply penetrating the crack Cr between the substrate surface layer and the inside of the substrate.

5 is a cross-sectional view schematically showing a stress gradient to be formed during laser brake processing. The substrate surface layer is heated for a short time to form the heating region (H). Then, large compressive stress HR is formed in the substrate surface layer, and under the influence, tensile stress CR is generated inside the substrate. If crack Cr exists inside a board | substrate, tensile stress will concentrate on the front-end | tip of crack Cr, As a result, crack Cr will penetrate deeper.

When the heating time of the substrate surface layer is lengthened, heat is transferred to the inside of the substrate, and the temperature difference generated in the depth direction becomes small. As a result, the stress gradient in the depth direction is weakened. Therefore, in the laser brake process, in order to set the compressive stress in the substrate surface layer, the heating condition in which the tensile stress is easily formed in the substrate, and the cooling condition, the heating condition that is strongly heated within a short time is selected in a temperature range in which the substrate is not softened. It is desirable to. In addition, by cooling the refrigerant by blowing it in advance before heating, the temperature difference in the depth direction may be increased, and tensile stress may be easily generated inside the substrate.

In addition, the reason why the deeper scribe line can be easily made by making the second initial crack deeper than the first initial crack will be described.

By setting the deep second initial crack Tr2 formed near the first substrate end A1 as the start end of the laser brake treatment, the initial position of the crack tip where the tensile stress is concentrated can be made the deep position of the substrate. In this state, by performing laser irradiation, a strong compressive stress is imparted to the substrate surface layer. As a result, the tensile stress is concentrated on the crack tip at the deep position, and the longer the distance from the substrate surface to the crack tip is, the greater the force (moment) trying to widen the crack acts in the direction of tearing the crack tip. As a result, the crack simply penetrates deeply.

In this manner, during the laser brake process, the second laser irradiation from the deep second initial crack formed at the first substrate end toward the second substrate end forms a scribe line made of the above-described deep crack Cr2. When the crack Cr2 reaches the rear surface, the substrate can be completely divided by the laser brake process.

The divided surface formed by this mechanism is very beautiful, and also has excellent straightness, and is in an ideal state as a processing cross section.

Next, the processing method which is 2nd embodiment of this invention is demonstrated. Here, the second initial crack Tr2 is formed by laser irradiation. It is a figure which shows the machining operation procedure of the laser brake process of the machining method which is 2nd Embodiment. In addition, since a laser scribe process is the same as FIG. 3, description is abbreviate | omitted.

By the same laser scribing process as to FIG. 3 (e), the scribe line which consists of the fin Cr of the finite depth starting from the position of the 1st initial stage crack Tr1 is formed in the board | substrate A. FIG. In this state, the process shifts to laser brake processing.

As shown to Fig.6 (a), the rotation table 12 is returned a little so that the 1st initial stage crack Tr1 may come under the optical holder 14. As shown to FIG.

Subsequently, as shown in FIG. 6 (b), the laser device 13 is operated to irradiate a laser beam, and the first initial crack Tr1 is heated, and the rotary table 12 (base 7) To move the beam spot to the first substrate end A1 side. Accordingly, the crack progresses from the first initial crack Tr1 toward the first substrate end A1, and the second initial crack Tr2 is formed so as to continue from the first substrate end A1 to the first initial crack. do.

Subsequently, as shown in Fig. 6 (c), the turntable 12 (base 7) is returned to its original position (position in Fig. 3 (a)), and the laser device 13 is operated to operate the laser beam. Investigate.

Subsequently, as shown in FIG. 6 (d), the substrate A is moved, and the beam spot formed on the substrate A is moved from the first substrate end A1 to the second substrate end A2 along the scribe line. Inject). As a result, the second initial crack Tr2 (that is, the first substrate end A1) is started, and the deep crack Cr2 proceeds along the crack Cr (scribe line), and the deep scribe line is moved to the second group. The determination is made up to A2.

In the two embodiments described above, both the second initial cracks were formed to be continuous with the first initial cracks, but if the initial cracks approached to some extent, even if they were not continuous, as a result of the laser brake treatment, the continuous It is possible to form a scribe line. Further, even if the second initial crack is formed at the first substrate end, a continuous scribe line can be formed if the distance to the first initial crack is sufficiently close.

INDUSTRIAL APPLICABILITY The present invention can be used for processing to form a deep scribe line or to completely divide a brittle material substrate such as a glass substrate.

2: slide table
7: base
12: rotating table
13: laser device
16: cooling nozzle
17 lifting mechanism
18: Cutter wheel with cycle groove
A: glass substrate (brittle material substrate)
BS: Beam Spot
CS: Cooling Spot
Cr: Crack
Cr1: deep crack
Cr2: Crack
Tr: initial crack

Claims (8)

As a processing method of a brittle material board | substrate which sets a scribing scheduled line which makes a board | substrate end into a brittle material board | substrate, and forms the crack of a finite depth along a scribe scheduled line,
Near the start end of the scribe scheduled line and at a position on the scribe scheduled line spaced apart from the start end in the substrate direction, the cutter wheel is pressed to form an initial crack spaced from the start end,
Subsequently, the beam spot formed on the surface of the substrate by laser irradiation is locally heated to a softening temperature or less by relatively moving along the scribe planned line while passing through the initial crack phase from the start end, and then the area of the locally heated region. A method for processing a brittle material substrate in which a crack having a finite depth starting from the position of the initial crack is formed along a scribe scheduled line by cooling immediately after. The method of claim 1,
A laser scribing method using a grooved cutter wheel having a cycle groove formed at the blade edge as the cutter wheel. The method of claim 1,
The laser scribing method of the separation distance from the beginning of a scribe plan line to an initial stage crack is 2 mm-7 mm. A method of processing a brittle material substrate in which the substrate is processed by performing two laser irradiations along a predetermined scribe line from the first substrate end set to the brittle material substrate to the second substrate end,
(a) a first initial crack formation step of forming a first initial crack by being spaced apart from the first substrate end on a scribe plan line near the first substrate end;
(b) The beam spot of the first laser irradiation is moved relatively from the first substrate end side to the second substrate end along the scribe scheduled line, and the substrate is heated to a softening temperature or lower, and the beam spot passes. A laser scribing step of cooling by spraying a coolant to a portion immediately afterwards and forming a scribe line having a finite depth along the scribe scheduled line;
(c) a second initial crack forming step of forming a second initial crack on at least one of the first substrate ends or the scribe scheduled line between the first substrate end and the first initial crack;
(d) a laser brake process in which the beam spot of the second laser irradiation is relatively moved along the scribe line from the first substrate end to the second substrate end so as to penetrate the scribe line even more deeply or completely divide it. A processing method of a brittle material substrate made. The method of claim 4, wherein
The second initial crack forming step of (c), wherein the second initial crack is continuously formed along the scribe predetermined line from the first substrate end to the first initial crack. The method of claim 4, wherein
The first initial crack and the second initial crack are formed by pressing the cutter wheel. The method of claim 4, wherein
The first initial crack is formed by pressing the cutter wheel, and the second initial crack is formed by partial irradiation of a laser from the first initial crack phase toward the first substrate end side. The method of claim 4, wherein
A method for processing a brittle material substrate, wherein the second initial crack is formed deeper than the first initial crack.

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